Probe Storage Container, Prober Apparatus, Probe Arranging Method and Manufacturing Method of Probe Storage Container

ABSTRACT

An object of the present invention relates to an arrangement of a manufactured probe in a prober apparatus without being exposed to an atmospheric air. 
     The present invention relates to a probe storage container which can supply a probe in a prober apparatus without being exposed to an atmospheric air. Preferably, the probe is stored in the probe storage container by removing an oxide film in a leading end portion of the probe in accordance with a dry treatment using an ion source or the like, without being exposed to the atmospheric air. In accordance with the present invention, it is possible to replace and attach the probe with respect to the prober apparatus without being exposed to the atmospheric air, and it is possible to avoid a formation of the oxide film on a surface of the probe. Further, a worker attaching the probe to the prober apparatus can work without being directly in contact with the probe, and it is possible to prevent the leading end portion of the probe from being broken. Accordingly, it is possible to stably measure an electric characteristic of a semiconductor device or the like on the wafer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of storing and manufacturing aprober apparatus which checks a position of a refined wiring or the likeon a semiconductor integrated circuit or the like by a scanning electronmicroscope, and measures an electric characteristic by bringing a probeinto contact with a wiring electrode or the like while monitoring astate by the scanning electron microscope.

2. Description of the Related Art

The prober apparatus is an apparatus for measuring an electriccharacteristic by bringing a probe into contact with a wiring positionwhile observing a refined wiring position on a semiconductor integratedcircuit by a microscope. In recent years, a measured portion becomesrefined on the basis of a micro-fabrication of the semiconductor, andcan not be checked by an optical microscope, and a scanning electronmicroscope utilizing an electron beam has been utilized. As a materialof the probe, it is demanded that the material has a durability and ishard, and further has a resistance against the electron beam, and atungsten or a tungsten alloy has been generally utilized.

The tungsten is easily tapered its leading end portion in accordancewith an electrolytic etching by an aqueous sodium hydroxide or anaqueous potassium hydroxide, however, has a defect that the tungstentends to be oxidized in an atmospheric air.

Accordingly, in order to increase a reliability of an electric contactof the tungsten probe, as a means end for achieving an oxidationprevention of a surface, there is shown a method of coating inaccordance with a plating after forming a leading end in a predeterminedshape, and a method of removing an oxidation preventing layer justbefore using a metal probe to which the oxidation preventing layer isapplied so as to use. Further, as a method of storing a powder andgranular material and a food product, there is shown a method of storingby a vacuum container.

Patent Document 1: Japanese Patent Application Laid-Open No. 6-109415

Patent Document 2: Japanese Patent Application Laid-Open No. 6-66557

Patent Document 3: Japanese Patent Application Laid-Open No. 9-262079

SUMMARY OF THE INVENTION

As a result of an eager study of the inventor of the present invention,the following problems have been known.

In the probe of the prober apparatus, the electric characteristic of theelectrode on the wafer can not be measured by an oxide film formed inthe leading end portion in the process of manufacturing the probe. Inparticular, in the case that the measured material is refined or aninterval between the measured materials becomes narrow, it is necessaryto taper the leading end portion of the probe, however, if a radius ofcurvature of the leading end portion becomes equal to or less than 50nm, it is impossible to secure a conduction with the measured materialdue to the oxide film on a surface of the leading end even if thetapered leading end portion is formed.

On the other hand, in the probe of the prober apparatus, it is necessaryto break a natural oxide film formed in the measured material by beingdirectly brought into contact with the measured material, and it isdesirable to employ a hard material having an improved conductivity anda durability, and further having an improved electron beam resistance.As means for securing the conductivity of the probe, there is a methodof coating the surface in accordance with a plating or the like,however, the plating material is peeled at a time of the contact withthe measured material, and there is generated a phenomenon that theelectrodes are short circuited by the peeled plating material.

On the other hand, in the metal probe in which the oxidation preventingfilm such as the resin or the like is applied to the leading endportion, it is necessary to remove the film just before the use.However, since a series of works are executed in the atmospheric air,there is a risk that the natural oxide film is formed in the probeleading end portion in some working environment state, working time andattaching time to the prober apparatus, or a foreign material isattached to the leading end portion in the process of removing the oxidefilm. Accordingly, the greatest care is necessary for the oxide filmremoving process. Further, there is a possibility that the leading endportion is broken by dropping the probe or making the leading endportion of the probe in contact at a time of attaching the probe.

An object of the present invention relates to an arrangement of amanufactured probe in a prober apparatus without being exposed to anatmospheric air.

The present invention relates to a probe storage container which cansupply a probe in a prober apparatus without being exposed to anatmospheric air.

Preferably, the probe is stored in the probe storage container byremoving an oxide film in a leading end portion of the probe inaccordance with a dry treatment using an ion source or the like, withoutbeing exposed to the atmospheric air.

In accordance with the present invention, it is possible to replace andattach the probe with respect to the prober apparatus without beingexposed to the atmospheric air, and it is possible to avoid a formationof the oxide film on a surface of the probe. Further, a worker attachingthe probe to the prober apparatus can work without being directly incontact with the probe, and it is possible to prevent the leading endportion of the probe from being broken. Accordingly, it is possible tostably measure an electric characteristic of a semiconductor device orthe like on the wafer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a prober apparatus mounting a scanning electron microscopetherein in accordance with a first embodiment;

FIG. 2 is a schematic view of a structure of a probe storage containerin accordance with the first embodiment;

FIG. 3 is a cross sectional view of the probe storage container inaccordance with the first embodiment;

FIG. 4 is a view showing an applied example of a milling apparatus inaccordance with the first embodiment; and

FIG. 5 is a schematic view of the prober apparatus using the probestorage container in accordance with the first embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

In the present embodiment, in order to prevent an exposure to theatmospheric air after removing an oxide film in a leading end portion ofa probe of a prober apparatus, a probe storage container capable ofsealing an inner portion is used, a storage and supply chamber isprovided in a prober apparatus having an oxide film removing step, aleading end portion shape measuring step and a scanning electronmicroscope, and an attachment of the probe to the prober apparatus froma removal of the oxide film is executed without being exposed to theatmospheric air.

FIG. 1 shows an outline of a prober apparatus mounting a scanningelectron microscope in accordance with the present embodiment. Theapparatus is provided with a sample chamber 3 having a probe unit 1moving a probe tracing a sample within the sample chamber and a samplestage 2 mounting the sample built-in, and a chamber in which the sampleand the probe are arranged, as a chamber in which the sample and theprobe are arranged. Further, the apparatus is provided with an electrongun portion 4 of an electronic optical apparatus constituted by anelectron source generating an electron, various apertures, a condenserlens for focusing the electron, a deflecting coil, an objective lens, anion pump making each of the portions high vacuum, a secondary electrondetector and the like, and a probe replacing chamber 5 capable ofreplacing the probe without breaking the vacuum of the sample chamber 3.Further, the apparatus is provided with a sample replacing chamber 6capable of replacing the sample without breaking the vacuum and anexhaust apparatus achieving a vacuum exhaust, as an exhaust mechanismcapable of exhausting the inner portion of the probe supply chamber.Further, the apparatus is structured by a control display portion 7constituted by a control apparatus, an image display portion, an imagedisplay control portion and a control display apparatus. A probe supplychamber 8 structured such that a vacuum exhaust can be achieved via agate valve and provided with a door portion to the chamber is added tothe sample replacing chamber 6.

FIG. 2 is a schematic view of a structure of the probe storage containeraccommodating the probe used for the prober apparatus, in accordancewith the first embodiment, and FIG. 3 is a cross sectional view of theprobe storage container in accordance with the first embodiment.

A probe 9 is formed by caulking and bonding a tungsten wire having adiameter of 0.05 mm and a length of 15 mm to a copper sleeve having adiameter of 0.5 mm and a length of 9 mm. A leading end portion of theprobe 9 is desirably made of a tungsten, a tungsten alloy or a metalprocessed in a needle shape. The bonded probe raw material iselectrolytic polished by NaOH water solution, a radius of curvature ofthe leading end is processed to 50 nm or less, and a total length is setto 10 mm. The radius of curvature of the leading end portion is checkedby a scanning electron microscope under an acceleration voltage of 5 kVand a magnification of 30000 folds. A storage base 10 corresponding to aprobe holding portion for holding the probe at a predetermined positionin an inner portion of the probe storage container is made of astainless steel, and is provided with a groove 10 a to which a copperpipe portion of the probe 9 is inserted, a clearance groove 10 b for thecaulked portion of the copper sleeve, a groove 10 c having a sufficientmargin for preventing the leading end portion of the probe from beingbrought into contact with a periphery, and a groove 10 d for taking outthe probe. Further, a hole 10 e is provided at a diameter 4 mm as areference position of the storage container 11, which forms a referenceportion for positioning the probe storage container with respect to theprober apparatus, and a long hole 10 f for determining a posture of thereference hole of the storage container 11 is provided. It ismanufactured at a dimensional accuracy equal to or less than 0.1 mm.With respect to the reference position, a pitch accuracy of each of thegrooves of the probe is set to be equal to or less than 0.1 mm. Further,in order to keep the inner portion of the probe in a vacuum state, afluorine O-ring is used as a buffering material a 13 in an upper lid 12corresponding to a lid portion capable of sealing the inner portion inwhich the probe is stored, and a surface coming into contact with theO-ring is mirror finished as a structure of a dovetail groove 14 forpreventing the O-ring from coming off. Further, the storage base 10 isprovided with an intake port 15 capable of exhausting an air in theinner portion, and a valve 16 shutting off an ambient air is provided ina leading end thereof. In other words, the probe storage container isprovided with the intake port for making the inner portion of thecontainer in a vacuum condition, and the valve for shutting off theinner portion of the container from the ambient air.

After exhausting the inner portion of the storage container 11constructed by the elements mentioned above and closing the valve, aholding block 17 for holding a state is provided. At this time, a vacuummeter for controlling the state of the inner portion may be additionallyprovided.

Further, if a gap exists between the upper lid 12 and the probe, ascratch is generated on a surface due to a vibration at a time oftransferring. Accordingly, it is preferable to put a buffering material18 in the lid side. At this time, it is desirable that the bufferingmaterial b 18 employs a material which is hard to generate an out gas ora material from which a gas is sufficiently discharged by burning out.

The material of the storage container 11 may be a plastic material inplace of the metal, however, if it is not a conductive material, anelectron is charged on a surface so as not to be measured at a time ofchecking the leading end shape by the electron microscope while thestorage base 10 being as it is. Accordingly, it is desirable that thematerial has a resistance against an electron beam and is constituted bya conductive material. Further, since there is a risk that the out gasis generated from the inner portion during the vacuum storage, it isdesirable that a mechanism for heating by a lamp heater or the like isprovided for previously burning out in the vacuum condition.

The stored number of the probe in the storage container 11 is set to sixadministratively. Although the stored number is not particularlydefined, a stored number having one or more larger than the number thatthe prober apparatus can set the probes, for example, the stored numberof six in the case that the number of the probes which can be set isfive, taking into consideration a recovery of the replaced probe.

After electrolytic polishing the leading end portion of the probe, theprobe is put in the storage base 10 one by one, the upper lid 12 is set,and the storage base 10 is evacuated by the exhaust apparatus, forexample, a dry pump until the inner portion comes to several Pascal, andis held by the holding block 17. At this time, a holding method of theupper lid 12 may employ a screw.

Next, a dry etching is applied for removing an oxide film formed in theleading end portion in the manufacturing step. The dry etching employs amilling apparatus which ionizes an argon in the vacuum and acceleratesan argon ion so as to process.

FIG. 4 shows a schematic view of the milling apparatus additionallyprovided with the storage container supply chamber.

At a time of manufacturing the probe storage container of the proberapparatus, the oxide film at least in the leading end portion of theprobe is removed by using the ion beam apparatus without being exposedto the atmospheric air, the probe is stored in the probe storagecontainer, and the lid portion of the probe storage container is closed.Specifically, it is executed, for example, as follows.

The storage container 11 in which the probe having the processed leadingend is put is mounted on a storage base stage 19. A pin is additionallyprovided in the storage base stage 19, whereby positions of the storagebase stage 19 and the storage container 11 are determined. Next, thestorage container supply chamber 20 is evacuated by a vacuum exhaustingapparatus constituted by a dry pump (DP), a turbo molecular pump (TMP)and the like. A vacuum state is monitored by a vacuum meter. The holdingblock 17 is detached by a block attaching and detaching mechanism 21,and the upper lid 12 of the storage container 11 is detached by an upperlid opening and closing mechanism 22. Next, a gate valve 24 is opened bya supply base feeding mechanism 23, and the storage container base 10 isset to a milling stage 25 for processing the milling apparatus. At thistime, since the storage container base 10 is processed in a tilted stateat a time of being milled, it is desirable to provide a holding means inthe milling apparatus side. Further, a holding mechanism may be providedin the storage container base 10 side. Further, since the milling stage25 is provided with a stage rotating mechanism 26 of an autorotationmechanism for executing the process while rotating on its own axis. Theargon ion is generated by an ion source 27, a gas supplying apparatus 28for supplying an argon gas, a neutralizer 29 for neutralizing the argonion and an ion source power supply 30.

The milling is executed by setting the milling stage 25 so as to come to45 degree with respect to the ion source. A condition for removing theoxide film is set by using a time for which a milling shutter 31 is openand a draw-out voltage in the ion source as a parameter. Further, if agold is coated in an inner side of the groove 10 c of the storagecontainer base 10, the gold is sputtered by the argon ion, and the goldis coated on the other portions of the probe than the portion to whichthe argon ion is irradiated, whereby it is possible to differentiate theportion from which the oxide film is removed, from the other portions.Accordingly, if a television camera enlarging the leading end portion isprovided, for example, in the probe take-out portion of the probeapparatus so as to observe the leading end portion, it is possible tocheck whether or not the milling process is executed, because the otherportions than the portion from which the oxide film of the probe isremoved is coated by the gold.

Further, it is possible to employ a milling method of taking out theprobe one by one from the storage base 10 so as to execute the milling.The diameter of the leading end may be finished to the predetermineddimension by the milling step in place of the electrolytic processmentioned above. In this case, since the oxide film in the leading endportion is removed in the step of finishing to the predetermineddimension, it is preferable to prevent the steps after the milling frombeing exposed to the atmospheric air.

After the milling process, the gate valve 24 is opened, the storagecontainer base 10 is taken out from the milling stage 25 by the supplybase feeding mechanism 23, and the upper lid 12 of the storage container11 is attached by the upper lid opening and closing mechanism 22. Next,the holding block 17 is attached by the block attaching and detachingmechanism 13 and the vacuum condition is held. After closing the gatevale 24, the storage container supply chamber 20 is open to theatmospheric air, and the storage container 11 is taken out. After takingout, the storage container 11 is put in an aluminum vacuum package, theatmospheric air in the inner portion is evacuated so as to be in thevacuum state, and the sealing portion is heated and sealed. At thistime, it is possible to achieve a long-term storage by putting adeoxidizer or a moisture absorbent within the vacuum package.

FIG. 5 shows a schematic view of the prober apparatus using the storagecontainer 11. At a time of arranging the probe in the prober apparatus,the probe storage container storing the probe is held at a predeterminedposition within the probe supply chamber of the prober apparatus, andthe probe supply chamber is evacuated. Further, the lid portion of theprobe storage container is opened within the probe supply chamber, andthe probe in the probe storage container is arranged in the chamber ofthe prober apparatus. Describing a specific example, at a time of usingthe probe in the prober apparatus provided with the scanning electronmicroscope, the storage container 11 is taken out from the vacuumpackage, the holding block 17 is detached, and the storage container 11is set to the stage of the probe supply chamber 8. The probe supplychamber 8 is evacuated by the dry pump, the upper lid 12 is opened bythe upper lid opening and closing mechanism 22 corresponding to thecontainer opening and closing mechanism capable of opening and closingthe lid portion of the probe storage container, and the probe isattached to a leading end of a probe holder 33 structured such that asupport pipe supporting the probe and an arm fixing the support pipe areintegrally formed, by a probe supplying mechanism 32 capable ofarranging the probe of the probe storage container in the chamber.

In the case of measuring an electric characteristic of a device of asemiconductor integrated circuit by using the probe manufactured asmentioned above, it is possible to secure a conductivity and measurewith a stable characteristic.

Further, the scanning type electron microscope provided with the upperlid opening and closing mechanism 22 is used for checking the radius ofcurvature of the leading end portion in a midstream step. The probestorage container 11 is set in a state of detaching the holding block17, and is set to the vacuum state by the dry pump, the upper lid 12 ofthe probe storage container 11 is detached by the upper lid opening andclosing mechanism 22, and the storage container base 10 is transferredto a sample observing stage 34 measuring from the sample chamber by thesupply base feeding mechanism 23. The leading end portion of the probeis observed at a magnification of 30000 folds by a scanning electronmicroscope constituted by an electronic optical system 35 discharging,accelerating and converging the electron, a secondary electron detector36 detecting a secondary electron output from the measured material, anexhaust apparatus holding the vacuum state, and the like. It isdesirable to sort the leading end diameter in correspondence to thediameter and the pitch of the measured material at a time of beingactually used, on the basis of the result of observation of the leadingend portion. Since the probe is not exposed to the atmospheric air inthe midstream step, there is not generated such a defect that themeasurement can not be executed due to the oxide film on the surface ofthe probe, and it is possible to stably measure the electriccharacteristic of the device in the semiconductor integrated circuit.

In accordance with the present embodiment, since the worker attachingthe probe can execute the replacing and attaching work without directlytouching the probe, it is possible to prevent the leading end portion ofthe probe from being damaged. Further, since the probe is not exposed tothe atmospheric air from the process of removing the oxide film in theleading end of the probe to the attachment to the prober unit of theapparatus, including the storage, the oxide film is not formed on thesurface of the probe, and it is possible to stably measure the electriccharacteristic of the semiconductor device or the like on the wafer.Accordingly, this is considered to be a technique necessary forevaluating the characteristic of the semiconductor device on the basisof the micro-fabrication of the semiconductor in the future.

Second Embodiment

In order to prevent the oxidation of the tungsten probe, the inner sideof the storage container may be replaced by an inert gas, for example, anitrogen or the like in addition to the vacuum state. In the presentembodiment, a description will be given of a case that the inert gas isfilled within the storage container while focusing on a different pointfrom the first embodiment.

In the milling step of the first embodiment, after removing the oxidefilm by the milling process of the leading end portion of the probe, adry nitrogen gas is introduced to the probe storage container 11 in thestorage container supply chamber 20 by an inert gas supplying apparatus37. The upper lid 12 is set by the upper lid opening and closingmechanism 22 at a time when the atmospheric pressure is achieved by thevacuum meter, and the holding block 17 holds the storage container 11 insuch a manner as to prevent the nitrogen gas from leaking. Next, thestorage container is taken out of the storage container supply chamber20, and is put in the aluminum package so as to be stored. At this time,it is possible to store for a long term by sealing the deoxidizer or thelike in the package.

At a time of actually using, the storage container is taken out from thealuminum package, and the storage container is set to the table of theopening and closing apparatus of the prober apparatus provided with theelectron microscope with the opening and closing apparatus. After thenitrogen is introduced after exhausting the inner side of the openingand closing apparatus by the vacuum exhausting apparatus so as to set tothe vacuum state, and the inner side of the chamber is filled with thenitrogen, the upper lid is detached. Next, the inner side of the chamberis set to the vacuum state by the vacuum exhausting apparatus, and theprobe is set to the holder. At this time, the opening and closing valvemay be opened after attaching the opening and closing valve to thestorage container and vacuum exhausting the inner side of the chamber,and then the upper lid may be detached by the opening and closingapparatus in the vacuum state.

In the case of setting the probe stored for one month in the storagecontainer mentioned above after the milling process to the probeapparatus, and measuring the electric characteristic of thesemiconductor, the conductivity can be secured, and the stablemeasurement can be achieved.

1. A probe storage container storing a probe used in a prober apparatus,comprising: a probe holding portion for holding said probe at apredetermined position in an inner portion of said container; areference portion for positioning said container with respect to theprober apparatus; and a lid portion capable of sealing an inner portionin which said probe is stored.
 2. A probe storage container as claimedin claim 1, wherein an oxide film is removed at least in a leading endportion of said probe.
 3. A probe storage container as claimed in claim1, wherein the other portions of said probe than the portion in whichthe oxide film is removed are coated by a gold.
 4. A probe storagecontainer as claimed in claim 1, wherein a leading end portion of saidprobe is made of a tungsten or a tungsten alloy.
 5. A probe storagecontainer as claimed in claim 1, wherein the probe storage container isprovided with an intake port for making an inner portion of thecontainer in a vacuum state, and a valve for shutting off the innerportion of the container from an ambient air.
 6. A probe storagecontainer as claimed in claim 1, wherein an inner portion of thecontainer is filled with an inert gas.
 7. A probe storage container asclaimed in claim 1, wherein an inner portion of the container is filledwith a nitrogen gas.
 8. A prober apparatus comprising: a chamber inwhich a sample and a probe are arranged; and a probe supply chamberprovided with a door portion to the chamber, wherein an inner side ofsaid probe supply chamber comprises: a holding mechanism for holding aprobe storage container for storing a probe used for the proberapparatus at a predetermined position; a container opening and closingmechanism capable of opening and closing a lid portion of the probestorage container; a probe supply mechanism capable of arranging theprobe in the probe storage container in the chamber; and an exhaustingmechanism capable of exhausting an inner portion of the probe supplychamber.
 9. A prober apparatus as claimed in claim 8, wherein an oxidefilm is removed at least in a leading end portion of said probe.
 10. Aprober apparatus as claimed in claim 8, wherein the other portions ofsaid probe than the portion in which the oxide film is removed arecoated by a gold.
 11. A prober apparatus as claimed in claim 8, whereina leading end portion of said probe is made of a tungsten or a tungstenalloy.
 12. A prober apparatus as claimed in claim 8, wherein the probestorage container is provided with an intake port for making an innerportion of the container in a vacuum state, and a valve for shutting offthe inner portion of the container from an ambient air.
 13. A proberapparatus as claimed in claim 8, wherein an inner portion of thecontainer is filled with an inert gas.
 14. A prober apparatus as claimedin claim 8, wherein an inner portion of the container is filled with anitrogen gas.
 15. A probe arranging method of arranging a probe in aprober apparatus, comprising the steps of: holding a probe storagecontainer for storing the probe at a predetermined position within aprobe supply chamber of the prober apparatus; exhausting an inner sideof the probe supply chamber; opening a lid portion of the probe storagecontainer within the probe supply chamber; and arranging the probe inthe probe storage container in a chamber of the prober apparatus.
 16. Aprobe arranging method as claimed in claim 15, wherein an oxide film isremoved at least in a leading end portion of said probe.
 17. A probearranging method as claimed in claim 15, wherein the other portions ofsaid probe than the portion in which the oxide film is removed arecoated by a gold.
 18. A probe arranging method as claimed in claim 15,wherein a leading end portion of said probe is made of a tungsten or atungsten alloy.
 19. A probe arranging method as claimed in claim 15,wherein the probe storage container is provided with an intake port formaking an inner portion of the container in a vacuum state, and a valvefor shutting off the inner portion of the container from an ambient air.20. A probe arranging method as claimed in claim 15, wherein an innerportion of the container is filled with an inert gas.
 21. A probearranging method as claimed in claim 15, wherein an inner portion of thecontainer is filled with a nitrogen gas.